Boat Outdrive Trim Tab

ABSTRACT

A trim tab device that serves as a propeller guard for a boat&#39;s motor is provided. The trim tab device includes a trim plate having a bracket removably mounted to a boat motor. A hollow cylindrical shell is integrally attached to a base portion of the trim plate. The hollow cylindrical shell defines an inlet opening and an outlet opening. The hollow cylindrical shell is configured to encircle a propeller of the boat motor. The hollow cylindrical shell directs waterflow through the propeller from the inlet opening to the outlet opening. A fin extends outwardly from the hollow cylindrical shell and is configured to securably attach to the boat motor.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/994,445 filed on May 16, 2014. The above identified patent application is herein incorporated by reference in its entirety to provide continuity of disclosure.

FIELD OF THE INVENTION

The present invention generally relates to trim tabs and propeller guards. More specifically, the present invention relates to a trim tab device that controls water flow along a trim tab with a propeller guard that directs the flow of water to the propeller of an outboard motor.

BACKGROUND OF THE INVENTION

Trim tabs are historically used to control the flight attitude of a boat by changing the localized slope of a portion of the bottom surface of the boat. Prior art trim tabs may be attached to the boat hull by hinges or solidly affixed and may either be held rigid or be made to flex by control means. Existing trim tabs are not configured to be controlled to provide increased water flow to the propeller. Existing trim tabs that are located in front of, and below, the propeller are used to limit variations of propeller blade immersion. Existing trim tabs are known which have flow limiting flood walls or flood curtains to decrease the flow of water to the propeller. Such existing trim tabs do not have means to increase the flow of water to the propeller, nor do they protect the propeller from damage.

Additionally, the propeller of an outboard motor typically rests below the bottom surface of the boat when in use, and propels the boat through the water. Due to its position during operation, the propeller of an outboard motor tends to be very susceptible to damage from under water objects such as rocks, sandbars, marine life, and the like. If the propeller of the outboard motor becomes damaged due to its impingement on underwater objects, it may become unable to perform as designed. The need for repair and/or replacement of a propeller damaged thus, generally occurs at very inconvenient times and is always a very expensive repair. Therefore, a need exists to develop a device which can control the flight attitude of a boat, as well as protect the propeller of an outboard motor to prevent it from being damaged by underwater objects.

Devices have been disclosed in the prior art that relate to trim tab devices and propeller guards. These include devices that have been patented and published in patent application publications. These devices generally relate to relate to trim tab devices that attach to the rear of a boat or boat motor. The following is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art.

Adding trim tabs to a boat changes the overall wetted area footprint of a bottom of the boat and thus will usually change the flight attitude of the boat. Boats with a propeller in a tunnel may have a fixed geometry closure panel as a continuation of the boat's bottom surface. For example, U.S. Pat. No. 6,464,549 to Buzzi refers to the closure panel as a “ground wall”, but it is in a fixed position and has only one opening and that is located where the propeller shaft emerges from the rearward end of a tunnel near the propeller. Buzzi describes the tunnel as having only a single opening and is not classified as a trim tab but instead as means to control flow around a propeller. The mere presence of Buzzi's closure in contact with the flowing water, however, changes the wetted footprint of the bottom of a boat.

U.S. Pat. No. 4,909,175 to Arnseson shows a flexing trim tab attached to the boat bottom, forward of the stern. Prior art trim tabs do not include a propeller guard to protect the propeller from being damaged or propeller screens to protect swimmers or marine mammals.

These prior art devices have several known drawbacks. Devices in the prior art fail to provide a trim tab device that controls water flow, wherein the trim tab device additionally serves as protection for a propeller for a boat motor. The present invention provides a trim tab device that also serves as propeller guard for a boat motor. The trim tab device includes a trim plate having a hollow cylindrical shell that is integrally attached to a base portion of the trim plate. The hollow cylindrical shell is configured to encircle a periphery of a propeller of the boat motor and directs waterflow towards the propeller.

In light of the devices disclosed in the prior art, it is submitted that the present invention substantially diverges in design elements from the prior art and consequently it is clear that there is a need in the art for an improvement to existing trim tab devices. In this regard the instant invention substantially fulfills these needs.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of trim tabs now present in the prior art, the present invention provides a trim tab that is mounted to the boat motor and encloses the propeller wherein the same can be utilized for providing convenience for the user when protecting the propeller from damage and to enhance lift.

It is therefore an object of the present invention to provide a new and improved trim tab device that has all of the advantages of the prior art and none of the disadvantages.

It is another object of the present invention to provide a trim tab device that serves as propeller guard for a boat motor. The trim tab device includes a trim plate having a bracket removably mounted to a boat motor. The trim plate is substantially triangular.

It is yet another object of the present invention to provide a hollow cylindrical shell integrally attached to a base portion of the trim plate. The hollow cylindrical shell defines an inlet opening and an outlet opening. The hollow cylindrical shell is configured to encircle a periphery of a propeller of the boat motor.

It is still yet another object of the present invention to provide a fin extending outwardly from the hollow cylindrical shell. The fin configured to securably attach to the boat motor.

It is another aspect of the present to provide a hollow cylindrical shell that directs waterflow to the propeller from the inlet opening to the outlet opening. The hollow cylindrical shell increases the area of the trim tab device, as well as maximizes the performance of an outboard motor having a propeller guard attached thereto.

It is yet another object of the present invention to provide a hollow cylindrical shell integrally attached to the base portion of the trim tab. The cylindrical shell is configured to surround a periphery of the boat outdrive. A fin extending outwardly from the cylindrical shell and is adapted to attach to the base of a boat motor.

Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout.

FIG. 1 shows a perspective view of the trim tab according to one embodiment of the present invention.

FIG. 2 shows a side perspective view of the trim tab according to one embodiment of the present invention.

FIG. 3 shows an overhead view of the trim tab according to one embodiment of the present invention.

FIG. 4 shows a side view of the trim tab according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the trim tab and propeller protector. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for boat outdrive motors. The figures are intended for representative purposes only and should not be considered to be limiting in any respect.

Referring now to FIGS. 1 and 2, there are shown perspective views of the trim tab device according to embodiments of the present invention. The trim tab device 100 serves a dual purpose as a trim tab and a propeller guard. The trim tab device includes a trim plate 102 having a bracket 104 that can be removably mounted to a boat motor via fasteners, such as bolts. In a preferred configuration, the trim plate 102 is substantially triangular. The trim plate 102 is generally in the form of a flat stainless steel plate that is pivotally attached to the transom or hull of the boat or boat motor. Trim plates 102 of different sizes are used, depending upon the size of the boat and boat motor.

The trim plates 102 provide additional boat control for reasons such as uneven load distribution in the boat, controlling bow attitude in various water conditions, and trimming the boat out of the water faster in conditions such as shallow water operation. Depending on the type of boat and the number and position of occupants, the attitude (or side-to-side angle along the keel) can tilt left or right. The trim plate 102 improves boat performance by leveling the boat. The trim plate 102 can also be used to increase top end speed and to provide a drier ride by keeping the nose down and the boat up on an even plane.

A hollow cylindrical shell 108 is integrally attached to a base portion of the trim plate 102. An exterior edge of the cylindrical shell 108 is affixed to the trim plate 102. The hollow cylindrical shell 108 defines an inlet opening 110 and an outlet opening 112 of a propeller. The hollow cylindrical shell 108 is configured to encircle a periphery of a propeller of the boat motor. The propeller of an outboard motor typically rests below the bottom surface of the boat when in use. The hollow cylindrical shell 108 protects the propeller from damage due to its tendency to be very susceptible to damage from underwater objects such as rocks, sandbars, marine life and the like. The hollow cylindrical shell 108 directs waterflow to the propeller from the inlet opening 110 to the outlet opening 112.

The trim tab device 100 further includes a fin 116 extending outwardly from the bottom of the hollow cylindrical shell 108. The fin 116 is configured to securably attach to the underside of the boat motor once the trim plate 102 is bolted to the motor. The fin 116 is preferably disposed on the side of the cylindrical shell 108 opposite the trim plate 102. The fin 116 provides a tapered shank extending from the hollow cylindrical shell 108. The waterflow across the outboard motor is facilitated by the tapered fin 116 and streamlines the waterflow. The fin 116 further includes a plurality of support bars 120 disposed on both sides of the fin 116. The support bars 120 provide a rigid connection between hollow cylindrical shell 108 and the fin 116. In some embodiments, when the trim tab device 100 is attached to an outdrive boat motor, the fin 116 rests below the outdrive boat motor.

Referring now to FIGS. 3 and 4, there are shown overhead and side views of the trim tab, respectively. The trim tab device 100 provides a hollow cylindrical shell 108 that encloses a boat propeller and is incorporated with a trim plate 102. The hollow cylindrical shell 108 closely encircles the propeller blades and guards the propeller against damage to the stern drive, and related mechanical components, such that there is a partial barrier between the propeller and the outside environment. Further, the trim tab device 100 enhances performance in directing water flow and alternatively can be utilized for helping to lift the rear area of the boat. The trim tab device 100 is fabricated from material comprising steel or aluminum, or a combination thereof.

The hollow cylindrical shell 108 directs the waterflow entering the boat motor. The hollow cylindrical shell 108 directs waterflow to the propeller from the inlet opening 110 to the outlet opening 112. In one embodiment of the invention, the hollow cylindrical shell 108 is formed with a convex tapper on the interior side of its inlet opening and a similar convex tapper on the exterior side of its outlet opening forming an arcuate tapered end surface 118. The hollow cylindrical shell 108 increases fluid pressure of the propeller, reduces or eliminate cavitation, and thus improves the performance characteristics of the motor. The hollow cylindrical shell 108 is secured to the motor with the aid of a bracket 104 and bolts which is preferably designed to minimize vibrations and other cyclical loading thereon in order to prevent premature metal fatigue, cracking, or failure.

It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 

I claim:
 1. A trim tab device that serves as propeller guard for a boat motor, comprising: a trim plate having a bracket adapted to removably mount to a boat motor, wherein the trim plate is substantially triangular; a hollow cylindrical shell integrally attached to a base portion of the trim plate, the hollow cylindrical shell defining an inlet opening and an outlet opening, wherein the hollow cylindrical shell is configured to encircle a propeller of the boat motor; and a fin extending outwardly from the hollow cylindrical shell, the fin configured to securably attach to the boat motor; wherein the hollow cylindrical shell is adapted to direct waterflow to the propeller from the inlet opening to the outlet opening.
 2. The trim tab device of claim 1, wherein the hollow cylindrical shell comprises steel or aluminum, or a combination thereof.
 3. The trim tab device of claim 1, wherein the hollow cylindrical shell directs the waterflow entering the boat motor.
 4. The trim tab device of claim 1, wherein the hollow cylindrical shell surrounds the propeller of the boat motor to form a partial barrier.
 5. The trim tab device of claim 1, wherein the trim plate is secured to the boat motor via the bracket and one or more fasteners.
 6. The trim tab device of claim 1, wherein the hollow cylindrical shell tapers from the inlet opening to the outlet opening forming an arcuate tapered end surface.
 7. The trim tab device of claim 1, wherein the fin is on the hollow cylindrical shell opposite the trim plate. 